SNAP: Study Nutrients in Adult PKU

The aim of this explorative cross-sectional study is to gain quantitative insights on blood nutrient levels of adult PKU patients on a protein substitute.

• Inclusion Criteria:

Both PKU and Non-PKU comparison subjects:

• Age ≥18 years
• Willing and able to provide signed informed consent PKU specific inclusion criteria
• PKU patients identified by newborn screening and started low Phe diet before 1 month age
• Usage of at least one Phe-free protein substitute (i.e. an amino acid mixture including micronutrients) on a daily basis for at least 26 consecutive weeks up to Visit 1

Non-PKU comparison subjects specific inclusion criteria:

• Same age- (±3 years) and sex as an included PKU subject

• Exclusion Criteria:

Both PKU and Non-PKU comparison subjects:

• For women: Currently pregnant or lactating
• Current psychiatric disorders
• Current Substance Use Disorders (as described in DSM V)
• Current use of psychotropic and/or inotropic medication
• Omega-3, antioxidant, (multi)vitamin and/or (multi)mineral supplement use within six weeks prior to entry in the study
• Severe hepatic, thyroid or renal dysfunction
• No acute illnesses like flu, diarrhea, or vomiting (subjects should be symptom free for a week prior to V1)
• Participation in any other clinical intervention studies involving test products concomitantly or within six weeks prior to entry into the study
• Other family members taking part in this study

PKU subject specific exclusion criteria:

• Use of BH4, or drugs that may interfere with main outcomes

Non-PKU comparison subjects specific exclusion criteria:

• Any condition or special diet (e.g. vegan or vegetarian diet) that effects the metabolism and/or normal dietary pattern/intake
• A first or second degree relative with inborn errors of metabolism
• Living together with someone with inborn errors of metabolism (e.g. partner, spouse or roommate)